1、raising standards worldwideNO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBSI Standards PublicationDD ISO/TS 10867:2010Nanotechnologies Characterization of single-wallcarbon nanotubes using nearinfrared photoluminescencespectroscopyDD ISO/TS 10867:2010 DRAFT FOR DEVELOPMENTNat
2、ional forewordThis Draft for Development is the UK implementation of ISO/TS10867:2010.This publication is not to be regarded as a British Standard.It is being issued in the Draft for Development series of publicationsand is of a provisional nature. It should be applied on thisprovisional basis, so t
3、hat information and experience of its practicalapplication can be obtained.Comments arising from the use of this Draft for Developmentare requested so that UK experience can be reported to theinternational organization responsible for its conversion toan international standard. A review of this publ
4、ication willbe initiated not later than 3 years after its publication by theinternational organization so that a decision can be taken on itsstatus. Notification of the start of the review period will be made inan announcement in the appropriate issue of Update Standards.According to the replies rec
5、eived by the end of the review period,the responsible BSI Committee will decide whether to support theconversion into an international Standard, to extend the life of theTechnical Specification or to withdraw it. Comments should be sentto the Secretary of the responsible BSI Technical Committee at B
6、ritishStandards House, 389 Chiswick High Road, London W4 4AL.The UK participation in its preparation was entrusted to TechnicalCommittee NTI/1, Nanotechnologies.A list of organizations represented on this committee can beobtained on request to its secretary.This publication does not purport to inclu
7、de all the necessaryprovisions of a contract. Users are responsible for its correctapplication. BSI 2010ISBN 978 0 580 61382 1ICS 07.030Compliance with a British Standard cannot confer immunity fromlegal obligations.This Draft for Development was published under the authority ofthe Standards Policy
8、and Strategy Committee on 30 September 2010.Amendments issued since publicationDate Text affectedDD ISO/TS 10867:2010Reference numberISO/TS 10867:2010(E)ISO 2010TECHNICAL SPECIFICATION ISO/TS10867First edition2010-09-15Nanotechnologies Characterization of single-wall carbon nanotubes using near infr
9、ared photoluminescence spectroscopy Nanotechnologies Caractrisation de nanotubes de carbone monofeuillet en utilisant la spectroscopie de photoluminescence dans le proche infra-rouge DD ISO/TS 10867:2010ISO/TS 10867:2010(E) PDF disclaimer This PDF file may contain embedded typefaces. In accordance w
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14、e postale 56 CH-1211 Geneva 20 Tel. + 41 22 749 01 11 Fax + 41 22 749 09 47 E-mail copyrightiso.org Web www.iso.org Published in Switzerland ii ISO 2010 All rights reservedDD ISO/TS 10867:2010ISO/TS 10867:2010(E) ISO 2010 All rights reserved iiiContents Page Foreword iv Introduction.v 1 Scope1 2 Nor
15、mative references1 3 Terms and definitions .1 4 Principles of band gap photoluminescence of SWCNTs 2 4.1 Structure of SWCNTs2 4.2 Band structure and PL peaks.3 4.3 Exciton effects .4 5 NIR-PL apparatus 4 5.1 NIR-PL spectrometer.4 5.2 Light source .4 6 Sample preparation methods.4 6.1 Preparation of
16、D2O dispersion for measurement.4 6.2 Preparation of solid film dispersion for measurement5 7 Measurement procedures.5 8 Data analysis and results interpretation.6 8.1 Empirical rules for structural assignment 6 8.2 Determination of the chiral indices of the semi-conducting SWCNTs in a sample .7 9 Un
17、certainties7 10 Test report8 Annex A (informative) Case studies9 Bibliography14 DD ISO/TS 10867:2010ISO/TS 10867:2010(E) iv ISO 2010 All rights reservedForeword ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The wo
18、rk of preparing International Standards is normally carried out through ISO technical committees. Each member body interested in a subject for which a technical committee has been established has the right to be represented on that committee. International organizations, governmental and non-governm
19、ental, in liaison with ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization. International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2. The
20、main task of technical committees is to prepare International Standards. Draft International Standards adopted by the technical committees are circulated to the member bodies for voting. Publication as an International Standard requires approval by at least 75 % of the member bodies casting a vote.
21、In other circumstances, particularly when there is an urgent market requirement for such documents, a technical committee may decide to publish other types of document: an ISO Publicly Available Specification (ISO/PAS) represents an agreement between technical experts in an ISO working group and is
22、accepted for publication if it is approved by more than 50 % of the members of the parent committee casting a vote; an ISO Technical Specification (ISO/TS) represents an agreement between the members of a technical committee and is accepted for publication if it is approved by 2/3 of the members of
23、the committee casting a vote. An ISO/PAS or ISO/TS is reviewed after three years in order to decide whether it will be confirmed for a further three years, revised to become an International Standard, or withdrawn. If the ISO/PAS or ISO/TS is confirmed, it is reviewed again after a further three yea
24、rs, at which time it must either be transformed into an International Standard or be withdrawn. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. ISO shall not be held responsible for identifying any or all such patent rights. ISO/T
25、S 10867 was prepared by Technical Committee ISO/TC 229, Nanotechnologies. DD ISO/TS 10867:2010ISO/TS 10867:2010(E) ISO 2010 All rights reserved vIntroduction Discovery of band gap photoluminescence (PL) of single-wall carbon nanotubes (SWCNTs) has provided a new way to characterize their unique elec
26、tronic properties induced by their low dimensionality. The method can provide the chiral indices of the semi-conducting SWCNTs in a sample and their relative integrated PL intensities. With the knowledge of their PL cross-sections, the relative mass concentrations of semi-conducting SWCNTs in a samp
27、le can be estimated. DD ISO/TS 10867:2010DD ISO/TS 10867:2010TECHNICAL SPECIFICATION ISO/TS 10867:2010(E) ISO 2010 All rights reserved 1Nanotechnologies Characterization of single-wall carbon nanotubes using near infrared photoluminescence spectroscopy 1 Scope This Technical Specification provides g
28、uidelines for the characterization of single-wall carbon nanotubes (SWCNTs) using near infrared (NIR) photoluminescence (PL) spectroscopy. This Technical Specification provides a measurement method for the determination of the chiral indices of the semi-conducting SWCNT in a sample and their relativ
29、e integrated PL intensities. The method can be expanded to estimate relative mass concentrations of semi-conducting SWCNTs in a sample from measured integrated PL intensities and knowledge of their PL cross-sections. 2 Normative references The following referenced documents are indispensable for the
30、 application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. ISO/TS 80004-3, Nanotechnologies Vocabulary Part 3: Carbon nano-objects 3 Terms and definitions For the purpo
31、ses of this document, the terms and definitions given in ISO/TS 80004-3 and the following apply. 3.1 chiral vector of SWCNT vector notation used to describe the helical structure of a single-wall carbon nanotube ISO/TS 80004-3:2010, definition 4.5 3.2 chiral indices two integers that define the chir
32、al vector of a single-wall carbon nanotube 3.3 relative mass concentration mass concentration of nanotube species relative to that of the most common nanotube species DD ISO/TS 10867:2010ISO/TS 10867:2010(E) 2 ISO 2010 All rights reserved4 Principles of band gap photoluminescence of SWCNTs 4.1 Struc
33、ture of SWCNTs An SWCNT consists of a single cylindrical graphene layer. The specific geometry of SWCNTs is defined in terms of a chiral vector containing a length (the tubes circumference) and a chiral angle (ranging from 0 to 30). Alternatively, the structure of SWCNTs is unambiguously defined by
34、the two integers, so-called chiral indices (n, m). Figure 1 shows the indexed graphene sheet with chiral vector for designating nanotube structure, and how the vector starting at point (0,0) to (n, m) determines the nanotube designation 1. The chiral angle is measured between the zigzag structure (
35、= 0) and the chiral vector. When the chiral angle is between 0 and 30, a chiral structure arises. The SWCNT having the maximum chiral angle, 30, is called the armchair SWCNT. NOTE The chiral angle and chiral vector are shown. The gray indices are for nanotubes that are not photoluminescent. Figure 1
36、 Indexed graphene sheet with chiral vector for designating nanotube structure 2 The length of the chiral vector is the circumference of the tube, or the tube diameter dt. The tube diameter dtis given in terms of (n, m) by 22CCt3/ammnndL+= where dtis the diameter of the SWCNT; L is the length of the
37、chiral vector; aCCis the nearest-neighbour distance (0,144 nm) between pairs of carbon atoms; m is one of the chiral indices; n is the other chiral index. DD ISO/TS 10867:2010ISO/TS 10867:2010(E) ISO 2010 All rights reserved 3The chiral angle in terms of (n, m) is defined by the equation ()1tan 3 /
38、2mnm=+where is the chiral angle; m is one of the chiral indices; n is the other chiral index. 4.2 Band structure and PL peaks Quasi-one-dimensional SWCNTs have an electronic density of states roughly as shown in Figure 2, with sharp van Hove peaks such as v1and v2(in the valence band) and c1and c2(i
39、n the conduction band). Figure 2 Qualitative description of the electronic density of states for SWCNTs 2 Just as the positions of the van Hove peaks depend on the structure (and chiral vector) of the particular SWCNTs, so will the absorption energy E22and fluorescent emission energy E11. Therefore,
40、 the positions of the spectral peaks corresponding to E22and E11are characteristic of the structure of each SWCNT, and can be used as a measurement method to determine the component SWCNTs of an unknown mixture. The following equation relates peak wavelength to transition energy /E hc hc= where E is
41、 energy of the transition; c is the speed of light; h is Plancks constant; DD ISO/TS 10867:2010ISO/TS 10867:2010(E) 4 ISO 2010 All rights reservedv is the peak position, expressed in wavenumber units (cm1); is the wavelength of the photon absorbed or emitted. Those structures where the difference (n
42、 m) is divisible by three e.g., (3,0), (4,1), or (6,3), and those structures where n = m, do not fluoresce because SWCNTs with (n m) = a multiple of 3 are semi-metals, with a band gap in the meV range, and those with n = m are metals (no band gap). The remaining structures are semi-conductors with a
43、 band gap of about 0,5 eV to 1 eV (1 eV = 1,602 176 53 (14) 10-19J), and can fluoresce under specific sample preparation conditions. NOTE As-prepared SWCNTs samples contain left- and right-handed helical structures. The peak positions of the PL signals are basically the same for these enantiomers. 4
44、.3 Exciton effects Electron-hole pair excitations giving rise to PL are better described in terms of excitons. Excitons are the result of Coulomb interaction, which for SWCNTs is very important and significantly affects the energy spectrum, for example with phonon sidebands and excitonic manifolds o
45、f excited states, and the strength of optical transitions. The exciton binding energy was estimated to be 0,420 eV for SWCNTs with the diameter of 0,8 nm in a polymer matrix and a surfactant solution 3. This value substantially depends on the nanotube environment. 5 NIR-PL apparatus 5.1 NIR-PL spect
46、rometer For SWCNTs produced by the chemical vapor deposition (CVD) method with typical diameter distribution of 0,6 nm to 1,3 nm, a NIR detector covering the spectral range from 800 nm to 1 600 nm is sufficient to detect their PL. However, to detect the PL signal of the larger diameter SWCNT produce
47、d by the laser vaporization and electric arc techniques, a spectral range of 1 200 nm 2 000 nm is usually required. NOTE 1 Examples of detector materials are InGaAs and InP/InGaAs. NOTE 2 The spectral resolution, which in a scanning monochrometer is a complex function of the bandpass of the monochro
48、mators, the stepping increment and slit width, needs to be adjusted to resolve the SWCNT peaks of interest in the sample. In general, bandpass values approaching 10 nm have been shown to be sufficient for most surfactant suspensions of SWCNTs. With multi-channel NIR detection systems, a resolution o
49、f 5 nm is recommended. 5.2 Light source Excitation sources are available such as monochromated Xenon or tungsten lamps, continuous Titan-Sapphire lasers or fixed wavelength diode lasers. NOTE Suitable wavelengths of diode lasers can be selected to suit the diameter distribution of the SWCNT sample (see Figure A.2 and Figure A.4). 6 Sample preparation methods 6.1 Preparation of D2O dispersion for measurement For the preparation of a liquid dispersion of SWCNTs, the following
